Effect of a Sciatic Block (SNB) Combined With a Continuous Femoral Block (CFNB) on Pain Scores After Knee Arthroplasty

Effect of a Single Shot Sciatic Nerve Block (SNB) Combined With a Continuous Femoral Block (CFNB) on Pain Scores After Knee Arthroplasty. A Randomized Controlled Trial

The purpose of this study is to determine if the addition of a sciatic nerve block (SNB) to a continuous femoral nerve block (CFNB) improves post-operative analgesia after knee arthroplasty.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain
• Intervention / Treatment: Procedure: CFNB; Procedure: SNB plus CFNB

Detailed Description

Background: Postoperative pain after total knee replacement /arthroplasty (TKA) is a major concern. It is severe pain in 60% of patients and moderate in 30%. Continuous femoral nerve blocks (CFNB) are considered an excellent choice for regional anesthesia for major knee repair but there are some controversies about the need of supplemental obturator or sciatic nerve blocks for achieving better postoperative analgesia. A recent meta-analysis states there is no sufficient evidence to recommend or discharge these associations.

Objectives: We aim to assess the efficacy of the association of a sciatic nerve block (SNB) and a continuous femoral nerve block (CFNB) for reducing postoperative pain in patients submitted to TKA. Methods: A randomized controlled study on 50 patients submitted to TKA. Control group receives a femoral nerve block with a catheter before general anesthesia is induced and the intervention group gets a similar block plus a single shot SNB before general anesthesia. Both groups start a continuous local anesthetic infusion through femoral catheter after the end of surgery and supplemental oral diclofenac and paracetamol. Pain scores are measured until 24h postoperatively, side effects and patient satisfaction are monitored.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Portugal
  • Porto, Portugal, 4099-001
    • Centro Hospitalar do Porto, Serviço de Anestesia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: ADULT; OLDER_ADULT; CHILD
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Unilateral total knee replacement

Exclusion Criteria:

• Contra-indication for general anesthesia
• Infection on puncture site
• Coagulation disorders
• Pre-existent neuropathies
• Allergies to local anesthetics, paracetamol, diclofenac and tramadol
• Severe dyspepsia
• Less than 50kg weigh
• Body Mass Index (BMI) greater than 40
• American Society of Anesthesiologists (ASA) Physical Status 4 or 5
• Absence of capacity to use the Visual Analog Score (VAS) scale
• Refusal to give informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: DOUBLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Continuous femoral nerve block (CFNB); A continuous femoral nerve block is performed for peri-operative analgesia and a bolus of 30 ml of ropivacaine 0.375% is injected before induction of general anesthesia and surgery starts. An infusion of 8ml/h of ropivacaine 0.2% is started in post anesthesia care unit (PACU) and maintained for 48h	Procedure: CFNB; A continuous femoral nerve block is performed for peri-operative analgesia and a bolus of 30 ml of ropivacaine 0.375% is injected before induction of general anesthesia and surgery starts. An infusion of 8ml/h of ropivacaine 0.2% is started in post anesthesia care unit (PACU) and maintained for 48h; Other Names: Ropivacaine; Peripheral nerve blocks; Local anesthetics; Femoral nerve block
EXPERIMENTAL: Single shot SNB plus CFNB; A single shot sciatic nerve block (SNB) is performed before surgery with 25ml of 0.2% ropivacaine in addition to the continuous femoral nerve block (CFNB) performed in the control group before induction of general anesthesia and surgery starts. An infusion of 8ml/h of ropivacaine 0.2% is started in Post anesthesia care unit (PACU) and maintained for 48h	Procedure: SNB plus CFNB; A single shot sciatic nerve block (SNB) is performed with 25 ml of 0.2% ropivacaine before surgery in addition to an isolated continuous femoral nerve block (CFNB) in the control group; Other Names: Ropivacaine; Peripheral nerve blocks; Local anesthetics; Femoral nerve block; Sciatic nerve block

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Analogue Scores (VAS) - Pain Scores Measured in mm (0-100)	Pain scores measured by Visual Analogue Score (VAS) scale at 15-30min after Post anesthesia care unit (PACU) arrival VAS is a 100mm scale to measure pain. 0mm - no pain 100mm - worst possible pain	15-30 min after arrival on post anesthesia care unit (PACU)
VAS Results - Pain Measured in mm (0-100)	VAS pain scores are measured by blinded investigators 12h after surgery . VAS scale: 0 - no pain 100 - worst possible pain	12h after surgery
VAS Results - Pain Scores Measured in mm (0-100)	VAS pain scores are measured by blinded investigators 24h after surgery . VAS scale: 0 - no pain 100 - worst possible pain	24h after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Satisfaction With Anesthesia Technique in Each Arm of the Study	Satisfaction with the anesthesia technique using a categorical scale with three levels: Bad Reasonable Good/Very Good A Fisher's Exact test is made to asses any differences in the distribution of patients in each arm to each level of the categorical scale	1 month after surgery

Collaborators and Investigators

• Sponsor: Centro Hospitalar do Porto
• Collaborators: Universidade do Porto
• Investigators: Principal Investigator: Raul MS Carvalho, MD, Centro Hospitalar do Porto

Study record dates

Study Major Dates

• Study Start: April 1, 2011
• Primary Completion (ACTUAL): February 1, 2012
• Study Completion (ACTUAL): March 1, 2012

Study Registration Dates

• First Submitted: April 15, 2011
• First Submitted That Met QC Criteria: April 15, 2011
• First Posted (ESTIMATE): April 18, 2011

Study Record Updates

• Last Update Posted (ESTIMATE): June 19, 2012
• Last Update Submitted That Met QC Criteria: May 17, 2012
• Last Verified: May 1, 2012

More Information

Terms related to this study

• Keywords: Postoperative pain; Knee arthroplasty; Sciatic nerve block; Peripheral nerve blocks; Femoral nerve block
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Pain; Neurologic Manifestations; Pain, Postoperative; Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Anesthetics, Local; Ropivacaine
• Other Study ID Numbers: TA 007/11(004-DEFI/007-CES)